Re: [PATCH] LoongArch: Fix an ODR violation

[chenglulu]

LGTM!

Thanks!

在 2024/2/2 上午5:54, Xi Ruoyao 写道:

When bootstrapping GCC 14 --with-build-config=bootstrap-lto, an ODR
violation is detected:

     ../../gcc/config/loongarch/loongarch-opts.cc:57: warning:
     'abi_minimal_isa' violates the C++ One Definition Rule [-Wodr]
     57 | abi_minimal_isa[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES];
     ../../gcc/config/loongarch/loongarch-def.cc:186: note:
     'abi_minimal_isa' was previously declared here
     186 |   abi_minimal_isa = array<array<loongarch_isa, N_ABI_EXT_TYPES>,
     ../../gcc/config/loongarch/loongarch-def.cc:186: note:
     code may be misoptimized unless '-fno-strict-aliasing' is used

Fix it by adding a proper declaration of abi_minimal_isa into
loongarch-def.h and remove the ODR-violating local declaration in
loongarch-opts.cc.

gcc/ChangeLog:

        * config/loongarch/loongarch-def.h (abi_minimal_isa): Declare.
        * config/loongarch/loongarch-opts.cc (abi_minimal_isa): Remove
        the ODR-violating locale declaration.
---

Bootstrapped on loongarch64-linux-gnu.  Not fully regtested but it
should be an obvious fix.  Ok for trunk?

  gcc/config/loongarch/loongarch-def.h   | 3 +++
  gcc/config/loongarch/loongarch-opts.cc | 2 --
  2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/config/loongarch/loongarch-def.h 
b/gcc/config/loongarch/loongarch-def.h
index a1237ecf1fd..2dbf006d013 100644
--- a/gcc/config/loongarch/loongarch-def.h
+++ b/gcc/config/loongarch/loongarch-def.h
@@ -203,5 +203,8 @@ extern loongarch_def_array<loongarch_align, N_TUNE_TYPES>
    loongarch_cpu_align;
  extern loongarch_def_array<loongarch_rtx_cost_data, N_TUNE_TYPES>
    loongarch_cpu_rtx_cost_data;
+extern loongarch_def_array<
+  loongarch_def_array<loongarch_isa, N_ABI_EXT_TYPES>,
+  N_ABI_BASE_TYPES> abi_minimal_isa;

#endif /* LOONGARCH_DEF_H */

diff --git a/gcc/config/loongarch/loongarch-opts.cc 
b/gcc/config/loongarch/loongarch-opts.cc
index b87299513c9..7eeac43ed2f 100644
--- a/gcc/config/loongarch/loongarch-opts.cc
+++ b/gcc/config/loongarch/loongarch-opts.cc
@@ -53,8 +53,6 @@ static const int tm_multilib_list[] = { TM_MULTILIB_LIST };
  static int enabled_abi_types[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES] = { 0 };

#define isa_required(ABI) (abi_minimal_isa[(ABI).base][(ABI).ext])

-extern "C" const struct loongarch_isa
-abi_minimal_isa[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES];

static inline int

  is_multilib_enabled (struct loongarch_abi abi)